Fuse.



L. W. DOWNES & R. C. PATTON.

FUSE.

APPLICATION FILED OCT- 23. 1915.

1 14,903 v Patented Feb. 6, 1917.

A? 45* I I IIIIIIA in '11,

avwwxtou Z 01/13" Zd DOZOJZZS,

Gum

renew each fuse after having been blown,

UNITED STATES OFFICE.

Louis w. nowN s AND RALPH CLIFTON rA 'rroN, or PROVIDENCE, mronn ISLAND,

- ASSIGNORS 'ro D a w rusncomrANY, or PROVIDENCE, RHODE ISLAND, a conro-RATION' 0F BHQDE ISLAND.

I FUSE.

Specification of Letters Patent.

Patented Feb. 6, 1917.

1 Application filed October 23, 1915. Serial No. 57,584.

dence and State ,of Rhode Island, have in vented certain new and usefulImprovements in Fuses, of which the following isa specification.

This invention relates to electric fuses of the class designed to openthe circuit when an excessive current passes through the line.

In some instances it is found desirable by the engineer or person incharge of the line controlled by these fuses, to personally by insertinga fresh fuse link therein. The

ordinary fuse is filled with granular arc suppressing material and upontaking the, same apart this material is often'scattered about and lost,and when the parts are returned, little or none ,is'replaced in thecasing. It will therefore be seen that a fuse which is designed tooperate safely by the use of such are suppressing material,. may now be.improperly assembled and therefore dangerous.

The object of this invention is to avoid this-contingency byconstructing a fuse that maybe safely operated without theuse of such afilling. This. is accomplished byproviding the usual tubular casing with010- I sures for its ends which areso formed that they provide atortuous restricted passageway for permitting and controllin the es capeof the gas which is generate therein by the volatilizing of the inclosedmetallic fuse link. I a

A further object ofthe/invention is to provide means in the casing nearits ends for exerting a cooling influence on the escaping gases, wherebythe excessive heat in the gas may be absorbed orconducted away beforereaching the-open, to such an extent as to prevent the possibility ofaflame passing through the escape passages to the outside of the fusecasing. I With these and other objects-in view, the invention consistsof certain novel features of construction as will be more fullydeappended claims.

In the accompanying drawings:-

Figure 1 is a sectional side elevation illustrating one form of fuse inwhich the closure members provide a tortuous restricted passageway forthe escape'of' gas generated in the casing.

Fig. 2 shows the end portion of a fuse having" another, construction ofend closure members. i

Fig. 3- shows the end portion of a fuse havingstill another constructionof end closure members.

Fig. 5 is a perspective view showing .a, pair of fuse links connected attheir ends to their respectivelink supports.

Fig. 6 is a perspective view showing one of thecontact blades and theriveting prov jection on one end thereof.

Fig. 7'is a sectional end view through the "casing showing the endclosure cup shaped members as corrugated so as to form a multiplicity ofpassageways to divide the escaping gascs'into small streams.

F g. '8,' is a sectional view showing a re-- movable flangeringpositioned on an inner cup member.

Referring to the drawings 10 designates the usual tubular form of casingwhich is preferably constructed of fiber or other suitable pressureresisting insulation material.

In this particular instance we have shown a pair of flat strip fuselinks 11 but any desired form of fuse link may be'employed.

These two links are shown as being connected by screws 12 to the yoke13, and this yoke is shown as being securedto the inner cup shaped endclosure member 14 by means of the lug 15 on the end of the contact blade16, which lug passes through correspondmg apertures in both the cup andthe yoke, and is spread, riveted or headed over as. at 17 on the insideof the latter, thus forming a unit as illustrated in Fig.4.

a The skirt portion 18' of this inner closure cup member is arranged toextend some distance into the end of the tube 10, to re-' inforcethe-end, and also provide an extended cooling surface over which theescaping gases must pas, and another cup shaped member19 is provided ofa size to fit over the outside of the casing 10. The

bottom portion of this cup is slotted at 20 to permit the blade 16 topass snugly therethrough. The skirt of this cup also serves to providean additional extended area across which the gases must also pass beforereaching the open.

As the object of this invention is to provide a'tortuous restrictedpassage at the ends of this casing through which the gases may escape,we have formed the inner cup with an outside diameter a little less thanthe inside diameter of the casing, and the inside diameter of the outercup, a little greater than the outside diameter of the casing, whereby anarrow space is left between the walls or skirt of both cups and thecasing for the passage of the gas.

Tn some cases to further restrict and better controlthis passageway wehave inserted a packing 21 of leather, or other suitable flexiblematerial, this nearly fills in the space between the bottom of the outercup and the end of the casing, the same serving to form a packing andmore surely close the central opening 20 about the contact blade 16against the passage of gases. It also guides the heated gases up andaround the end of the tubing to cause them topass back be-' other caseswe have provided a metal ferrule 23 on the outer surface of the tubeend. In either of these constructions it will be seen that the escapinggas will have to flow between two metal walls while passing through theescape passages. Thus. very complete cooling is-eflected and even underthe most severe conditions no flame can begforce from the fuse.

In some cases instead of providing a packing member 21 for deflectingthe course of the gas, we have, as illustrated in Fig. 2, provided anoutwardly turned flange 24: on

the edge of the inner cup shaped closure, whereby the escaping gases aredeflected up-- ward and then outward through the space 25 left betweenthe outer cup and the casing.

Fig. 3 illustrates still another construction in which a separate-plate27., is secured to the inner cup 28, and to the link supports 13 byrivetingthe contact blade 29 thereto, which plate is of a size to extendover the rare-nee ends of the tube 10 to serve as a deflector for theoutwardly rushing gases to direct them radiallyoutward and cause them topass back beneath the surface of the outer cup.

When a flange construction such as that illustrated at 24 in Fig. 2, isemployed, we have found it necessary to provide its equivalent at theopposite'end, in the form of a loose flange ring, such as thatillustrated at 32 in Fig. 8 or at 27 Fig. 3. This ring is formedseparate and independent of the cup member and is removably positionedthereon, by which construction this'cup member may be passed through thecasing after the fuse links have been connected to their yoke members.This permits this unit to be repositioned in the casing, and the flangering 32 to be subsequently positioned on its cup 33,the whole then beingsecured in position by the outer caps and screws as above described.

Anotheradvantage of the structure shown in Fig. 2, is that theescapinggas passes between the inner skirt 18 and the reinforcing ferrule 22with great velocity. Therefore these gases impinge strongly against theprojecting flange 24 which serves to cool the gases and condense themetallic vapor to a great extent. This is due to the fact that whenthese gases strike directly against a flat metallic surface, the gasstream is broken up into innumerable eddies and cross-currents bringingpractically all particles of the gases into contact with the coolingsurface. The temperature of the gases after contact with the flangeQk'is further lowered by its subsequent passage through the annularopening between the outer cap 19 and the tube 10.

Tn other cases instead'of forming the inner closure cup smaller than theinside of plicity of passages through which the gases escape in smallstreams.

llt will be seen by our improved construe tion that in order to removethe internal parts of the fuse, it is only necessary to remove thescrews 26 at. both ends of the casing, withdraw the end members, thenrei move the screws 12 from the link supports, insert a pair of freshfuse links 11, and rescrewdriver, and further by this construction itwill be seen that when the fuse is thus repaired and the parts replacedthat the same is as good as new and when reof closure members, but otherconstructions and arrangements of parts may be employed if desired, thescope of the invention being defined and limited only by the appendedclaims.

We claim: 7

1. An electric fuse comprising a fuse link, a link inclosing casing, endclosures therefor, and means including a sleeve portion on the outsideof the casing end and a sleeve portion on the inner side of the casingend providing between them an extended cooling area over which theescaping gas generated within the casing must pass.

2. An electric fuse comprising a fuse link, a link inclosing casing, endclosures therefor, means including a sleeve member on the sideof thecasing end and a sleeve member on the outer side of the casing endproviding between them an extended cooling area over which the escapinggas generated Within the casing must pass, and means for reversing thedirection of travel of the gas on its way to the open.

, 3. An electric fuse comprising a fuse link,

- a casing therefor, cup-shaped closures covering the ends of saidcasing, said closures being provided with vent openings, and meanswithin said casing coiiperating with said closures for spreading theescaping gases into a thin film both inside and out-- side of the casingto facilitate cooling.

4. An electric fuse comprising a fuse link, a casing therefor,acup-shaped closure extending into the inside and one extending over theoutside of said casing ends and attached thereto, passageways beingprovided between the caslng walls and those of both the inner'and outercups for relieving the gas pressure when generated within the casing. 5.An electric fuse comprisin a fuse link, a casing therefor, a cup-shapedclosure extending into the inside and one extending over the outside ofsaid casing ends and attached thereto, passageways being provided.between the casing walls and those ofjboththe inner and outer cups forrelieving gas pressure when generated within the casin 6.- An electricfuse comprising a fuse lin a link inclosing casing, two cup-shapedclosure members secured to each end thereof, one of said membersextending inside and one over the outside of said casing end, said innercup being provided with an end gas deflecting flange and passa ewaysbeing provided between the walls 0 said closures and casing for theescape'of gas.

7. An electric fuse comprising a fuse link, a link inclosing casing, twocup-shaped metallic closure members secured to each end thereof, one ofsaid members extending inside and one over the outside of said casingend, passageways being provided be- 9. An electric fuse comprising afuse link, i

a link inclosing casing, two cup-shaped metallic closure members securedto each end thereof, one of said members extending inside and one overthe outside of said casing end, thevlatter being secured to the casing,passageways being provided between the walls of said closure and casingfor the escape of gas, and means between the inner and outer closuresfor deflecting the escaping gases outwardly.

10. An electric fuse comprising a fuse link, a link inclosing casing,two cup-shaped metallic closures, one fitting loosely into and one overthe outside of each end of said casing, the skirts of each closureproviding an extended cooling area over which the heated escaping gasesmust pass, both cups at each end being secured together and one of eachpair being secured to the casing.

11. An electric fuse comprising a fuse link, a link inclosing casing,two cup shaped metallic closures secured to the casing, one fittingloosely into and one over the outside of each end of said casing, theskirts of each providing an extended cooling area over which the heatedescaping gases must pass and means cotiperating with said cups forincreasing the cooling effect upon'the escaping gases.

12. An electric fuse comprising a fuse link, a link inclosing'casing,two cup shaped closure members secured to each end thereof, one of saidmembers extending inside and the other over the outside of said casingend, passageways being provided between the, walls of said closures andcasing' for the escape of gas means codgerating with the walls of saidclosures for increasing the cooling effect upon the escaping gases, saidclosures being removably connected to said casing.

In testimony whereof we afiix our sigma-

